Daily Current Affairs : 28-June-2023
The Indian monsoon season faces the imminent threat of the El Nino phenomenon this year. However, there is hope that the development of a positive Indian Ocean Dipole (IOD) can counterbalance the adverse effects of El Nino. This essay explores the concept of IOD, its similarities to El Nino, its potential to mitigate El Nino impacts, and a comparison of their respective effects.
Understanding the Indian Ocean Dipole (IOD)
The IOD is an ocean-atmosphere interaction that occurs in the Indian Ocean, similar to El Nino in the Pacific Ocean. However, the IOD is a weaker system and consequently has relatively limited impacts. It is often referred to as the “Indian Nino” due to its similar nature to El Nino.
IOD and Its Regional Influence
The IOD primarily occurs in the smaller area of the Indian Ocean, spanning between the Indonesian and Malaysian coastline in the east and the African coastline near Somalia in the west. It manifests as a temperature anomaly, with one side of the ocean becoming warmer than the other. A positive IOD is observed when the western side near the Somalia coast becomes warmer than the eastern Indian Ocean, while a negative IOD occurs when the western Indian Ocean is cooler.
The Indian Nino and El Nino
In a typical year, the eastern side of the Pacific Ocean near the northwestern coast of South America is cooler than the western side near the islands of Philippines and Indonesia. This temperature difference is a result of prevailing wind systems that transport warmer surface waters towards the Indonesian coast, causing cooler waters from below to rise and replace the displaced water. During an El Nino event, the weakening of wind systems reduces the displacement of warmer waters, resulting in the eastern side of the Pacific becoming warmer than usual. This phenomenon suppresses monsoon rainfall over India.
Impacts of IOD
A positive IOD has a beneficial impact on rainfall along the African coastline and the Indian subcontinent, while simultaneously suppressing rainfall over Indonesia, Southeast Asia, and Australia. Conversely, a negative IOD event brings about opposite effects. However, it is important to note that compared to El Nino Southern Oscillation (ENSO) events, the impacts of IODs are generally weaker.
The Potential of IOD to Counterbalance El Nino
Given that the El Nino phenomenon is expected to affect the Indian monsoon this year, there is optimism that a positive IOD could mitigate its impacts to some extent. Past experiences, such as the remarkable performance of the IOD in 1997, suggest that it can effectively counterbalance El Nino’s adverse effects in neighboring regions.
Important Points:
- The Indian Ocean Dipole (IOD) is an ocean-atmosphere interaction similar to the El Nino phenomenon in the Pacific Ocean.
- IOD is a weaker system compared to El Nino and has limited impacts.
- A positive IOD can potentially counterbalance the impacts of El Nino, as observed in 1997.
- IOD is sometimes referred to as the “Indian Nino” and occurs in the Indian Ocean between the Indonesian and Malaysian coastline in the east and the African coastline near Somalia in the west.
- The temperature anomaly in IOD causes one side of the ocean to become warmer than the other.
- A positive IOD is characterized by warmer waters near the Somalia coast, while a negative IOD indicates cooler waters in the western Indian Ocean.
- In a normal year, the eastern side of the Pacific Ocean near South America’s northwestern coast is cooler than the western side near the islands of Philippines and Indonesia due to prevailing wind systems.
- El Nino occurs when the weakening of wind systems leads to warmer waters in the eastern Pacific, suppressing monsoon rainfall over India.
- A positive IOD enhances rainfall along the African coastline and the Indian subcontinent while reducing rainfall over Indonesia, Southeast Asia, and Australia.
- Compared to El Nino Southern Oscillation (ENSO) events, the impacts of IODs are weaker.
- The development of a positive IOD is anticipated to mitigate the adverse effects of El Nino on the Indian monsoon.
- Monitoring and understanding the IOD are crucial for managing and anticipating the effects of El Nino and maintaining stable monsoon conditions.
Why In News
Given the high likelihood of the El Nino phenomenon impacting the Indian monsoon this year, the anticipation for a favorable Indian Ocean Dipole (IOD) has intensified, as it holds the potential to mitigate the adverse effects of El Nino. As meteorologists closely monitor these interconnected climate patterns, the positive development of the IOD remains a beacon of hope for maintaining a balanced monsoon season in India.
MCQs about Countering El Nino’s Impact on Monsoons
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What is the primary difference between the Indian Ocean Dipole (IOD) and El Nino?
A. IOD has stronger impacts than El Nino
B. IOD occurs in the Indian Ocean, while El Nino occurs in the Pacific Ocean
C. IOD suppresses rainfall, while El Nino enhances rainfall
D. IOD is a more frequent phenomenon than El Nino
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What happens during a positive Indian Ocean Dipole (IOD) event?
A. Eastern side of the Indian Ocean becomes warmer
B. Rainfall increases in Indonesia, Southeast Asia, and Australia
C. African coastline experiences reduced rainfall
D. Indian subcontinent receives enhanced rainfall
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Which event suppresses monsoon rainfall over India?
A. Positive Indian Ocean Dipole (IOD)
B. Negative Indian Ocean Dipole (IOD)
C. El Nino
D. El Nino and Indian Ocean Dipole have equal impact
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Compared to El Nino Southern Oscillation (ENSO) events, how strong are the impacts of Indian Ocean Dipole (IOD)?
A. IOD impacts are stronger than ENSO events
B. IOD impacts are weaker than ENSO events
C. IOD and ENSO events have similar impacts
D. IOD impacts vary depending on the year
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